Safety type vertical door mounting and operating control



May 11, 1948. R. w. NEW 2,441,503

SAFETY TYPE VERTICAL Doon MOUNTING AND OPERATING coNTRoI.

Filed -May 1o, '1945 .2 sheets-sheet 1 R. w.` NEW 2,441,503

SAFETY TYPE VERTICAL DOOR MOUNTING AND OPERATING CONTROL May 11, 1948.

2 SheiS-Sheeb 2 Filed May lO, 1945 INVENTOR.V Roy W. MSW

Patented May 11, 1948 l, UNITED PA'rENr CE 'A j SAFETY.mra'vnalcAL-,Booa-Menmmc ANDv QPERATING- GNT'ROLI- RoyWinNew; Covi'n'gtj"on, Ky.,v assigner v t4 Blum Manufacturing flompanygnincinnnti;

Ohioiaicorporationof Ohi'o' Application 1943,*Se1'i3l-Nm 186;465

'l-Glms. (Cl. lime-175)" The present inventionv relates toindustria-4l"oyenA doors `oftheverticallyvoperating type, andhasor aniobjectthe-provision of-asaf'etyftype ofverticalf door mounting andfoperating control Anotherobject of the'invention is to provide' for safe and easybperatlon' oflarge andheavy oven doors of this type Witha minimumof power consumption; Y

A further -object of the invention is to provide a doorrmountling Vand control? whereby theJ door is Asnugly sealed: whenin fnllyy closedpositionand, at" ailvv other times, is movable freely withoutV dangerof' damage tothe heat seal about' the-door opening'in the oven. v

Still another-l obj ect of' the invention 'isv to pro'-r vide an arrangement' whereby1 danger 'to 'persons andw property iselimin'ated i'n the eventof 1-fedlure of the v4counterweight mechanism.

These and other'iobjects'are attainedfby the means herein described'L and disclosed in the ace' companying drawings; injwhich:

Figi. `1 isaront end` elevational` view- 'of an industrial: ovenV embodying Vt-l1e'-'door control lof the invention, parts being'brolen away; fandparts being shown in cross-section;

Fig; 3 is` a cross-sectionalview-'taken on line ile-3u of" Fig. 22 Y 4is a cross-sectiona View taken* on lineY 4-4-1ofFig. 1. 1

The utilization of vertically opening doors on oneonboth-'ends of'4 industrial ovens hasbecorne increasinglycommonlinltl'ie various-'fields of pro duction-due Atothe vnumerous advantagesinsaving Y' I of floor space in the plant and reducing congestion in movingmaterials by trucks into' and aroundthe ovens; The llargeand heavy-doors of this type have presentedahazardito'the'safety of'persons, material andcquipm'eni irr'the past, due tofthe fact-'that they-*were suspended by cables `or 'chains extending ovedpnlleysandfhaving counterweights. Breakagefoffthe'counterweig-htlmechanisrnalways-fv endangered persons ande'quipment beneath, and 'even partial breaktual damage to'fthe ovenf strncture jitself'unless' the" lazt'ter wereY vconfstructed-` more sturdily than otherwise requiredi bytne normalL duty? oftlie'in-V dustrial' oven.

the*presentI invent-ionan are obviated Y With refrmcetothedrayvings; itist'o be noted that' industrielli ovens of tatie-class; herein illus-A trstedeare frequently provided with a doorat each" fend; and that si-'nce' the doors and their monnting-*andcontrolmechanisms areisubstekntial duplicates,- 'only one end ofthe oven' need yIoe de scribedefrafli andiemit-plete`V limiter-standingy of" theinvention: Y Y

v In Fig. 1 theoven is indicatedgenerallyat- Ill; andl is-Ypreiterabl yA `eonsi'iruct'ed'fo'fl' metalcl-a'df insulating sidewall@ IIf' and metal-'clad insulating' roofing imnels if@ airranged' 'to form a tunneli- Sii'a'ped bbdyf dsidfl'engtin Vheightand Width tol accommodtef the"v imss'agcU of` trucks o1f-foonA veyorsior vc a-rryingln'xat'erialsito rbe' subjected to drying, baking" or tlieflik'e;

I# secure'chtoliti *The* sturdy upriglt's lextend upve'ardlyi` substantiailyf twice the height` of; the ovenlandtheportionsmbevetheovenroof! lfmayhaaren-,wher.structuralrmembersl` (not shown) .securedto theminknown mannerto supportheating, and; air circulating equipment (not-f shown) for-theorem im Ithe* space above the roof YP2VLA in order 4to.save:floorenlace. Y

Secured tothe outer.` faces of-- said frontguide plates I6' andto the outer faces of the ,rear guide plates 11 .are cross channels 20-and2I.,respec tivelg'. which' connect`the upright I5.` on either sidelof '.the doorway and also" form a mounting fortlief' 'door operating mechanism" hereinafter describedV Mon-ntedon the inner'opplosedifaces of gnideipatesA I Grand I lTa-re -guidlanglesj'and 23`, respectively. 'ai cen'nnjon "siiej of'these I,guide xandj25, re-

age*frequently'imposeddangerous strainsorfae2i 5o spectiirely. Y canrbb'est" seer in Fig; 4, the

guide angle 22 on the front guide plate I6 extends almost the full length of said plate. A short distance from the lower end of the plate, the guide angle 22 has a widened portion aifording an offsetting of the free edge of said guide angle at 2B and a short arcuate shoulder 21 at the junction of the offset. The guide angle y23 is arcuately cut away on its free edge at 28 slightly above the level of the opposed shoulder 21. The shoulders 21 and 28 together form an abrupt curve, toward the inside face of rear guide plate I1, in a wheel guide slot bounded by the salient edges of guide angles 22 and 23. ,On this inside face of guide plate I1 is a heat seal strip 29.

In a similar fashion, guide strips 24 and 25 form a wider and shorter guide wheel slot which terminates at its lower end a short distance below"Y the level of the top of door opening I3. 'I'he guide strip 24 has a shoulder 3 8 corresponding to shoulder 21 on guide angle 22 and the-guide stript.

' is. A(see Fig. 2.)

little power by the following described operating and safety holding mechanism.

This mechanism is built into and supported by the uprights I5 and the cross-members which connect said uprights at their tops. The mechan'ism consists generally of a power driven jack screw 46 rotatably supported in each upright i5, jack nuts 41 on said screws, with links 48 connecting said nuts with the blocks 43 on the top of the door 32, the jack screws having sprockets 49 fixed thereon and connected by drive chains 50 and 5I, respectively, ywhich 1 are carried by sprockets 52 on a reversible vertical motor 53.

The lower end of each jack screw 46 is journalled in a bottom flanged end bearing 54 which is secured to an angle bracket 55 secured to the face of the channel member I8 of the upright The upper end of each jack ,screwf4 is journalied in a bearing 5B secured to is shouldered or cut off at 3l corresponding to shoulder 28 on guide angle 23.

Mounted on opposite vertical edges of able guide wheels 33 which travel in the guide slot defined by guide strips 24 and 25. Near the bottoms. of the vertical vedges of door 32 are smaller guide wheels 34 each having an enlarged spacer or flange 35 to assure that said V wheels 34 shall follow in the guideslots betweenguide angles 22 and 23. Y

It will be noted, from an inspection of Fig. 4, that when guide wheels 33 and 34eng age shoulders 3i) and 21 respectively during downward movement of the door, said door will be shifted bodily from a vertical plane wherein the inside face of the door clears the heat seal strips 29 to a position of firm abutment against said seal strips without any appreciable scraping of said door on said strips.

The location of said shoulders with relation to the oven floor 35 and of. the guide wheels with relation to the bottom of the doorfis such that the door automatically seals the opening at the approximate instant it touchesthe floor, and breaks said seal, without scraping over the heat seal strips as soon as the bottom ofthe door leaves thefloor.

It should be noted thattheedge of the roof I2, above the door opening I3, terminates in the plane of the rear faces of guideplates I1 (see Fig. 3), and that a depending insulating flange 35 which denes the topV of door opening VvI3 has a heat seal strip 31 thereon,nthe; face of which lies in a common plane with the` faces of heat seal strips 29.' t 1 The weight of the door 32 is counterbalanced by means of a pair of cables 38 which pass over pulleys 39, through holes 40 in channel members I8 of the uprights, and over pulleys 4I on the brackets 420i atthe tops of uprights I5. Cables 38 are suitably attached to'rings 42' in the tops of blocks 43 from which the door is suspended. Counterweights 44 on the ends of the cables operate within vertical casings 45 at opposite sides oftheoven. j

The door and its mountingv as thus far ydescribed form a sort of unitarystructure which does not depend uponl the strength of the body of the associated ovenfor itssupport, but on the contrary, it provides ample support for a structurally weak oven body if such be desired. The door 32 is nicely counterbalanced and is therefore adapted to be` raised orflowered with very vthe verl' Y tical oven door 32 near the top are freely rotatj a plate5-1which is secured to the top end edges .,ofiguide plates :I6 and I1, as by welding, and which plate has a bore through which the jack screw extends into its bearing. A

vImmediately under the respective drive chains are vertically adjustable chain guide sheets 58 and `53, adjacent the edges of which are upright guard sheets 60 and .6, I which spanthe space between the uprights to give lthe Ventire structure a nished appearance yand prevent chains 50 and 51| from being .accidentally disengagedfrom the sprockets or from dropping to the floor in the event they zbecome loose .orY broken. Y Y

By reference to Fig. 2 it will be noted that the jack nut 41 has an integral trunnion 62 over Iwhich passes the upper perforated end oflink 48, while the block 43 on the door has a trunnion 63 to receive the lower endof said link.V It will be readily understood thatvthis linkage suspension of the door 32 in cooperation with the upper and lower guide wheels 33 and 34 riding between their angle guides and guide strips respectively, will insure free and easy raising and lowering movement whenever` the motor 53 is operated in the proper direction. The normal slow pitch of the threads on the jack screw and its nut will positively arrest and-.hold the door at any elevation when the motor is at rest. Even in the event of breakage of one or both of the counterweight cables 38 the door is precluded from falling' by the linkage and jack nut suspension.

The action of the door guide wheels at the shouldered portions of the guideslots is such that the door retains its vertical `position and also shifts bodily to and from a tightly sealed relation with the oven doorwayas the door reaches or leaves a fully lowered position in its vertical movement. This actionis completely automatic and permits of the use of materials in theheat sealing strips that are most effective but which wouldnot hold upunder a sliding contact with the door.

The wiring and-controlswitch stations (not shown) for the reversible motorv 53'may be disposed according to approved practices and convenience. v

The operation of the deviceand its eiiciency and complete safety will be fully understood from the foregoing description. l Y

For normal raising and lowering of the door the current consumption of motor is very low because the great weight of the large door 32 is fullycounterbalancedby the weights 44, and the motive power 4required is but littlegmore than enough to drive the 'jack Vscrewsand overcome a small amount of inertia in the masses and fricmemos? tion in the moving parts, Ifj desired the motor may be selected to raise andlower the door only l whenthe counterweights and cables arealso eifec'tivefto sustain the weightnof'v-the door' and in that wayprecludetheoperation in the event offailureeither of thecables 358i g j Whenthe-'door isfullyclosedit is held snugly againstA the heat sealstrips duej to its weight and the action' of*n its guide iv/heelson the shoulders of the guide strips and guide-angles and-more particularly because theA threaded engagementI of the jack screws in the jack nuts constitutes an irreversible connection. This tight seal protects persons not only against the discomfort of heat leakage around the door, but when the oven is used for baking enamels or lacquers on articles in the oven the danger to persons near the door is eliminated in the event of an explosion.

The door mounting and control of the invention will in practice render unnecessary the compulsory inspections currently required in the industries for vertical doors, because there is no danger of a falling door even though the counterweight mechanism fails. Furthermore, the guided condition of the door precludes injury to the hand of the worker if the hand should be inserted between the door and the front guide plate of the upright.

There is thus attained a Very high degree of safety from all of the hazards that normally attend the use of industrial ovens and at the same time the control of the door is simple and entirely automatic.

What is claimed is: Y

1. In a vertical door mounting and operating mechanism for an industrial oven the combination of avpair of vertical uprights defining the sides of an oven door opening and extending above such opening, means on said uprights forming guide slots, a vertical door extending between the uprights, guide members on the door and engaging the guide forming means and operating in the guide slots for normally retaining the door in slightly spaced relation to the uprights when the `door is at least partially raised, shoulders on the guide slot forming means downwardly inclined toward the door opening and spaced from the bottoms of the uprights at distances corresponding to the spacing of the respective guide means on .the door from the bottom of the door whereby the door is moved into and from sealing abutment with the uprights as the door moves into and from a fully lowered position, power driven jack screws mounted in the uprights, cooperating jack nuts on said screws, links pivotally connected at opposite ends to the sides of the jack nuts and the top of the door with their pivotal axes disposed horizontally in a plane parallelV with the major faces of the door for raising and lowering said door and pulley-supported cable and counterweight means normally sustaining the weight of the door.

2. In a vertical oven door mounting and operating structure the combination with a vertical oven door, of a pair of vertical uprights disposed one at each side of theV door, each upright comprising a front guide plate and a rear guide plate between which plates a Vertical edge margin of the door may freely operate, vertical guide angles disposed in opposed relation on adjacent faces of said guide plates of each upright to form a guide slot between them and provided with oilset shoulders downwardly inclined toward said rear guide plate at a predetermined elevation from the basev of the upright, guide strips secured alongside there'spective guide; angles to form between theml anothergui'de slot amil provided. with odset.,

shouldersinclined .dolwnwardljrv toward saidirear guide plateatia diierentelevationafrom the-base o'ff the upright', a pair Aet igu'dewheel's on Aeal'rhrside.

ofthe door and arranged foroperationone each.

inY the respective'guide-slots lin peripherallytrackingen'gagement with. the edges of said. guidel angles and 'said :guide rstrips respectively, .said--y wheels being vertically spaced yapar-t yfrom each" other `ata distance substantially equal to the distance between the first-mentioned offset shoulders and the second-mentioned -oifset shoulders, and means; for raising,` and lowering the vdoor comprising power driven jack screws-mounted4` in-,thev respective uprights, jack nuts on said jack screws and links pivotally connected at their opposite ends to the sides of said jack nuts and the top of the door, the pivotal axes of said links being disposed horizontally in a plane parallel to the major faces of the door.

3. In an industrial oven the combination oi insulating sidewalls having a doorway opening therein, a pair of uprights disposed respectively at opposite sides of said opening, a vertically movable door extending between the uprights and overlapping the opposite sides of the doorway opening, counterweight means for suspending the door in vertically adjusted positions, irreversible power driven means comprising vertical jack screws supported by the uprights and jack nuts thereon, means including pivoted links forming a flexible connection between said nuts and the top of the door and having their pivotal axes disposed horizontally in a plane parallel with the major faces of the door for raising and lowering said'door, cooperating guide' means on said uprights and the side edges of the door adjacent thereto for holding the door in non-contacting relation to the uprights when the door is disposed at any elevation above a fully lowered position, one of said guide means including inclined shoulders arranged-and adapted for contact with the other of said guide means when the door is disposed closely adjacent a fully lowered position for bodily shifting said door to and from contact with the uprights as said 'door is moved into and from fully lowered position opposite the door opening.

4. In an industrial oven the combination of a sidewall provided with a door opening, a pair of opposed, channel shaped uprights at the vertical sides of the door opening, a vertical door having its side edges extending into the opposed openings of the channel shaped uprights, guide wheels rotatably mounted adjacent the top and bottom of each side edge of said door and disposed in offset planes parallel to said edges of said door, parallel strips secured in opposed relation on opposed inner faces of said channel shaped uprights forming guide slots and tracking edges for diametrically opposite sides of each of said guide wheels, the strips engaged by the upper guide wheels being sloped in the direction of the door opening at a distance above the bases of the uprights corresponding approximately to the location of said Vupper guide wheels from the bottom of the door, the strips engaged by the lower guide wheels being inclined toward the door opening at a distance from the bases of the uprights corresponding to the approximate distance of the lower guide wheels from the bottom of thek door, the inclined portions on all of said guide strips engageable by the respective guide wheels on the door for shifting the door bodily to and from abutment with the uprights at the sidesof the door opening, as said door is moved vertically to and from fully lowered. position, and means for raising and lowering the door including synchronously drivenV jack screws supported on the uprights, jack nuts travelable thereon, and links connected at opposite ends with said nuts and theV top of the door with the pivotal axes thereof disposed horizontally in a plane parallel with the major faces of the door.

, ROY W. NEW.

REFERENCES CITED Thefollowing references are of record in the le of this patent:

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